JPS63265514A - Protective device for power distribution equipment - Google Patents

Abstract

PURPOSE:To enhance the reliability of protection against an accident on a load side by breaking a load breaker, if a malfunction detection means of said load breaker does not output a malfunction signal when a load protective relay detects an accident, and by breaking a receiving breaker, if said malfunction detection means outputs a malfunction signal. CONSTITUTION:When a load breaker 1 is closed and a gas pressure of said load breaker 1 is lowered, both a closed state signal SC and an actuating signal SG of a gas pressure switch 13 are outputted and inputted to an AND gates 24 and 25 respectively. In this case, if an accident happens, for example, on a motor side, a load protective relay 4 detects said accident and a relay actuating signal SR is outputted. Then, the logic of the AND gate 25 is realized continuously from that of the AND gate 24 and a breaking command signal TP2 being an output of the AND gate 25 is given to a receiving breaker 2 to cause said breaker to start a breaking action. Thus, an accident point is separated from a receiving end.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to two protective bags for high voltage power distribution equipment.

[Conventional technology]

Figure 2 is a Mitsubishi Gas breaker published by Mitsubishi Electric <SF
It is a single-line diagram of the main parts of the high-voltage power distribution equipment shown on page 7 of the catalog of ``G type''.

The power receiving end PS is connected to the bus 5 via a power receiving circuit breaker 2 consisting of a gas circuit breaker, and a power receiving protection relay 3 is installed in the middle of the line connecting the power receiving circuit breaker 2 and the bus 5 to detect an accident on the bus 5. has been established.

A motor 6 is connected to the bus bar 5 via a load breaker 1 consisting of a gas circuit breaker, and the same load breaker 1 as described above!
1.1, the primary sides of the power receiving transformers T and T are connected, and the secondary sides thereof are connected to various loads (not shown). A load protection relay 4 for detecting an accident on the load side is provided in the middle of each line connecting each load breaker l and the motor 6 or the power receiving transformer T.

Figure 3 shows the control circuit of the power receiving circuit breaker 2 or the load circuit breaker.
A series circuit is connected to the switch 17, a gas pressure switch 12 that opens when the gas pressure of the gas circuit breaker decreases, and a closing coil 15 of the circuit breaker. A tripping command contact 18, a gas pressure switch 13 that is interlocked with the gas pressure switch 12, an auxiliary contact 14 that is interlocked with the main contact of the circuit breaker and becomes closed when the main contact is closed, and a tripping coil 16 of the circuit breaker. series circuits are connected to each other. Furthermore, the tripping command contact 18
The operating contacts 19 of the load protection relay 4 are connected in parallel.

The part surrounded by the one-dot chain line is the internal circuit IO provided in the circuit breaker.

FIG. 4 shows an X-break control logic circuit for the load breaker 1 corresponding to the circuit shown in FIG.

Tripping signal SA output when tripping command contact 18 closes
A relay operation signal SR outputted when the relay operation contact 19 of the load breaker 4 is closed is input to the OR gate 20. On the other hand, the closing state signal SC output when the auxiliary contact 14 of the load breaker 1 is closed, and the operation signal SG of the gas pressure switch 13 output when the gas pressure switch 13 opens due to a decrease in the gas pressure of the gas circuit breaker 1. NO? The signal is input to the NO gate 22 via the circuit 21. In other words, A
When the gas pressure is normal, a non-operation signal NG (high) of the gas pressure switch 13 is input to the ND gate 22. Then, the output of the OR gate 20 and the AND gate 22
The output of ^ND gate 23 is inputted to the AND gate 23, and the output of the ^ND gate 23 is given to the tripping coil 16 of the load breaker 1 as a cutoff command signal, so that the load breaker 1 is cut off. Such a cutoff control logic circuit is the same for the power receiving protection relay 3 and the power receiving circuit breaker 2.

In FIG. 2, when the closing command contacts 17 of each circuit breaker are closed, the closing coil 15 is energized, and the power receiving circuit breaker 2 and the load are disconnected! 31 is turned on, and power is supplied to the motor 6 and the power receiving transformers T, T.

When power is being supplied to the load in this way, the auxiliary contact 14 is closed when the load breaker l is turned on, and the gas pressure switch 13 is closed when the gas pressure of the gas breaker is normal. There is. Therefore, the ON state signal SC and the non-operation signal NG (high) of the gas pressure switch 13 are input to the AND gate 22. This AND gate 2
The output of 2 (high) is input to the AND gate 23. In this state, for example, if an accident occurs in the motor 6, the load protection relay 4 installed on the line connected to the motor 6 detects the accident and operates, and the relay operation signal SR is transmitted via the OR gate 20. The signal is input to the AND gate 23, and the logic of the AND gate 23 is established. Therefore, the tripping coil 16 is excited and the load breaker l operates to disconnect the fault point on the motor 6 side from the bus bar 5.

On the other hand, an accident on the busbar 5 side is detected by the power receiving protection relay 3,
The relay operation signal SR causes the power receiving circuit breaker 2 to perform a breaking operation, and the fault point on the bus bar 5 side is separated from the power receiving end ps.

Also, when the closing command contact 17 is closed, the gas pressure switch
A current flows through the closing coil 15 through the 7-chip 12, the closing coil 15 is excited, and the load breaker 1 is closed.

In addition, when the gas pressure of the gas circuit breaker has decreased, the gas pressure switch 13 is opened and its operation signal SG is
(high) and a non-operation signal (low) is input to the AND gate 22 to prevent the tripping coil 16 from being energized. Prevents damage accidents.

[Problem that the invention seeks to solve]

When the gas pressure of the load breaker l has decreased in this way, the gas pressure switch 13 opens and its operating signal S
Since G (high) is output, the non-operation signal NG of the gas pressure switch 13 is not input to the NO gate 22.
Therefore, the logic of AND gate 22 does not hold, so load is cut off! When iS1 does not shut off and the gas pressure drops, the load breaker l is protected by prohibiting the shutoff operation. However, even if the load protection relay 4 detects an accident and outputs the relay operation signal SR, the logic of the NO gate 23 does not hold, so the load breaker l does not operate to interrupt the fault, and the fault point cannot be isolated from the bus 5. There is.

In view of the above-mentioned problems, the present invention has been devised so that when the abnormality detection means of the load breaker does not output an abnormality detection signal, when the load protection relay detects an accident, the load breaker is operated to cut off the fault, and the abnormality detection means When the load protection relay detects an accident while the load protection relay outputs an abnormality detection signal, the power receiving circuit breaker is operated to cut off the fault, thereby reliably isolating the fault that has occurred on the load side from the healthy line. The purpose is to provide.

[Means for solving problems]

The protection device of the present invention has a first
gate, and a second gate which receives the output of the first AND gate and the detection signal of the abnormality detection means for detecting abnormality of the load breaker.
and a third AND gate to which an inverted signal of the detection signal and the output of the first AND gate are input.

[Effect]

When the load protection relay operates in a state where the load breaker is turned on and the abnormality detection means of the load breaker is not outputting an abnormality detection signal, the load breaker performs a breaking operation. When the load protection relay operates while the load breaker is closed and the abnormality detection means outputs an abnormality detection signal, the power receiving circuit breaker operates to interrupt the load.

Therefore, if the abnormality detection means of the load breaker detects an abnormality, the power receiving circuit breaker shuts off the fault, so that the fault point is always isolated from the healthy line.

〔Example〕

The present invention will be described in detail below with reference to drawings showing embodiments thereof.

FIG. 1 shows a cutoff control logic circuit for cutting off a power receiving circuit breaker 2 and a load circuit breaker 1, which are essential parts of a protection device for power distribution equipment according to the present invention. The closing state signal SC of the load breaker 1 and the relay operation signal SR of the load protection relay 4 are connected to the first AN
The signal is input to the D gate 24.

The output of this AND gate 24 and the operation signal (detection signal jsc) output when the gas pressure cusp inch (abnormality detection means) 13 detects a decrease in the gas pressure of the gas circuit breaker are input to the second AND gate 25, and The output of the gate 25 is given to the power receiving circuit breaker 2 as a cutoff command signal TP2.The output of the AND gate 24 and the gas pressure switch 1
Is the operation signal SG of 3 NO? The third AN via circuit 26
The signal is input to the D gate 27.

That is, a non-operation signal NG, which is an inversion of the operation signal SG of the gas pressure switch 13, is input to the AND gate 27.

Therefore, the output of the AND gate 24 is input to the AND gate 27, and the logic is established when the operation signal SG is not output. The output of this AND gate 27 is the load cutoff command signal TPI! given to 11.

Next, the operation of the protection device of the present invention configured as described above will be explained in the first section.
This will be explained with reference to the drawings and FIG. In FIG. 2, power is supplied to the load by turning on the power receiving circuit breaker 2 and the load circuit breakers 1, 1.1. When the load breaker 1 is closed, a closing state signal SC is output.

On the other hand, when the gas pressure of the load breaker 1 is normal, the gas pressure switch 13 is closed and does not output the operation signal SG. Therefore, the NOT circuit 2 is connected to the ND gate 27.
A non-operation signal NG (high) which is the output of 6 is input. In such a state, if an accident occurs on the motor 6 side, for example, the load protection relay 4 installed on the line to which the motor 6 is connected will detect it, the relay operation contact 19 will close, and the relay operation signal SR will be output. Output. As a result, the logic of the AND gate 24 is established, and its output is input to the AND gate 27.

Therefore, the logic of the AND gate 27 is established, and its output is applied as a cutoff command signal TPI to the load shedding 81 to perform a cutoff operation. Therefore, the fault point in the mokro example is separated from the bus bar 5.

In addition, when the load breaker 1 is closed and the gas pressure of the load breaker 1 is decreasing, the closing state signal SC and the operation signal SG of the gas pressure cass inch 13 are both outputted, and the AND Gate 24 and AND gate 25
are each entered. At this time, if an accident occurs on the motor 6 side, for example, the load protection relay 4 detects it as described above and outputs the relay operation signal SR. Then, the logic of the AND gate 25 is established following the AND gate 24, and the output of the AND gate 25 is i! ! ! A disconnection command signal TP2 is given to the power receiving circuit breaker 2 to cause it to perform a disconnection operation. Therefore, the fault point is separated from the power receiving end ps. At this time, the output of the AND gate 24 is input to the HE-N log gate 27, but since the operation signal SG of the gas pressure switch 13 is output, the non-operation signal NG (high) is not input to the AND gate, and the AND The logic of gate 27 does not hold.

Therefore, the load breaker 1 is not given the interruption command signal TPI, and the load breaker When the circuit breaker 1 performs a circuit breaker operation, and if a similar accident occurs when the gas pressure is lowered, the power receiving circuit breaker 2 performs a circuit breaker circuit. In other words, regardless of the gas pressure of the load breaker l, if an accident occurs on the load side, the accident point will be disconnected from the healthy line.

Although this embodiment has described backup protection when the gas pressure of the gas circuit breaker decreases, it can also be applied to backup protection when an abnormality occurs in the circuit breaker drive mechanism or its control circuit.

〔Effect of the invention〕

As described in detail above, according to the present invention, the abnormality detection means of the load breaker detects an abnormality (when No. 3 is not output,
When the load protection relay detects an accident, the load breaker performs a cutoff operation, and when the load protection relay detects an accident while an abnormality detection signal is being output, the power receiving breaker performs a cutoff operation.

Therefore, even if there is an abnormality in the load breaker, the fault point can be reliably separated from the healthy line, and the reliability of protection against accidents on the load side can be improved.

[Brief explanation of drawings]

Fig. 1 is a logic circuit diagram for interrupting power receiving circuit breakers and load breakers, which are the main parts of the protection device for power distribution equipment according to the present invention, Fig. 2 is a single line diagram of the main parts of high-voltage power distribution equipment, and Fig. 3 is a Circuit breaker control circuit diagram FIG. 4 is a circuit breaker control logic circuit diagram of a power receiving circuit breaker and a load circuit breaker of a conventional power distribution facility. 1...Load breaker 2...Power reception! ! VFR device 3...
・Power receiving protection relay 4...Load protection relay 13...
Gas pressure cusp inch 24.25...AND gate 2G
. . . N07 circuit 27 . . AND gate In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. A protection device for power distribution equipment that supplies power to a load via a power receiving circuit breaker and a load circuit breaker that are operated to interrupt in relation to relay operation signals of a power receiving protection relay and a load protection relay, a first AND gate into which a closing state signal of the load breaker and a relay operation signal of the load protection relay are input; a first AND gate output and a detection signal of an abnormality detection means for detecting an abnormality in the load breaker; a second AND gate, an inverted signal of the detection signal and a first A
a third AND gate into which the ND gate output is input;
A protection device for power distribution equipment, characterized in that it is configured to interrupt a load breaker using an ND gate output.